In order to reduce the transmission cost, wireless network operators usually provide multimedia broadcast services of massive data in a form of multicast and broadcast service (MBS). MBS is classified into two categories, namely, the Single-BS MBS and the Multi-BS MBS. The Multi-BS MBS is advantageous in that, a plurality of BSs transmits data at the same frequency synchronously, so saving of bandwidth resources and the macro-diversity effect can be achieved, and data can be received by a mobile apparatus with enhanced reliability.
FIG. 1 depicts a schematic view of MBS zones 11, 12 involved in a wireless network system that provides MBS. The MBS zone 11 comprises at least one (e.g., seven) cell, which is represented by seven hexagons in the left portion of FIG. 1 and one of which is a cell 111. Each of the cells is served by a BS, which is represented by a dark dot inside a corresponding hexagon of FIG. 1; for example, the cell 111 is served by the BS 111a. The BS located within the MBS zone 11 belongs to the MBS zone 11 and provides MBS. Similarly, the MBS zone 12 comprises at least one (e.g., seven) cell, which is represented by seven hexagons in the right portion of FIG. 1 and one of which is a cell 121. Each of the cells is served by a BS, which is represented by a dark dot inside a corresponding hexagon of FIG. 1; for example, the cell 121 is served by the BS 121a. The BS located within the MBS zone 12 belongs to the MBS zone 12 and provides MBS. Furthermore, a mobile apparatus 111b is located within the cell 111. The mobile apparatus 111b operates in a power-saving mode and has to receive MBS data within the MBS zone 11.
Because each MBS zone has its own MBS configurations, the mobile apparatus must receive the MBS configurations at first before being able to receive the MBS data. MBS configurations are classified into non-cell-specific MBS configurations and cell-specific MBS configurations. A non-cell-specific MBS configuration is common data to a whole MBS zone, examples of which are an MBS MAP and an MBS data. In contrast, a cell-specific MBS configuration is related to a specific BS in the MBS zone, examples of which are an MBS zone boundary indicator, an MBS MAP resource index, an MBS region resource index (comprising a location and a size of an MBS region), an MBS modulation coding scheme (MCS), an MBS transmission interval and a neighbor MBS flows mapping list.
In the prior art, if the MBS provided in the wireless network system supports the macro-diversity, then a BS transmits a non-cell-specific MBS configuration in an MBS region of a frame, and transmits a cell-specific MBS configuration in other regions of the frame. If the mobile apparatus continuously stays in the power-saving mode, it would fail to receive the cell-specific MBS configuration and, consequently, fail to receive the MBS data successfully. For this reason, the mobile apparatus must switch into an active mode to continuously search for the frame in order to obtain the cell-specific MBS configuration. However, this makes it impossible to save power of the mobile apparatus, thereby causing unnecessary waste of the power resource.
Moreover, when moving from the cell 111 of the MBS zone 11 to the cell 121 of the MBS zone 12, the mobile apparatus 111b must perform an MBS location update procedure in order to continuously receive the MBS data. However, in the prior art, the mobile device 111b has no way to know the cell-specific MBS configuration related to the BS 121a in the MBS zone 12 in advance, so this will cause delay and/or interruption in the MBS data transmission.
Accordingly, there is an unmet need in the art to provide a solution that allows the mobile apparatus to derive the cell-specific MBS configuration in advance or in real time so as to avoid waste of the power resource and delay and/or interruption in the MBS data transmission.